Respective inspection standards have been defined in each of the production processes of integrated circuits, and sampling inspection or 100% inspection have been severely conducted in each of such production processes. Namely, lot production control whose unit is 1 cassette (25P) or 2 cassettes (50P), etc. has been usually carried out. Also, such an inspection system as should a trouble or a defective be found in each of the production processes it can be fed back to the processes before has been adopted, in order to solve such a problem as a trouble or defective as early as possible.
For this, it is necessary to clarify the history of every wafer one by one. Therefore, every wafer has been conventionally marked with name of product, serial number, etc. in a manual manner. There is unreasonable points, e.g. imbalance of character profile (thickness, depth, size, etc. of lines) according to differences of individuals in marking jobs by hand writing (or marking). In addition, given pen impression by hand marking may damage or injure wafers. Therefore, handling wafers which are expensive need careful attention, thereby causing the marking speed to be slowed down. If marking is done with weak impression, marking itself may disappear in subsequent processes and can not be seen.
Although a method that mechanically performs this is proposed, it restricts the position to be marked, thereby causing productive problems in continuously marking on successively provided substrates. Alternately, a laser marking device has been developed. This laser melts down the surface of some area of a wafer by means of laser light and marks there with a required character size. It can indeed solve a problem of wafer damages and can contribute to stabilization of character size. However, spatters may be produced on the surface (all or in the vicinity of marking area) of said wafer when melting it down by laser light, and area in the vicinity of melting down may be built up. It will adversely influence upon the subsequent processes, especially upon light exposure process. Furthermore, there are still another problems in stabilization of laser generation device, service life of laser itself, large scaling of said device itself, and increase of the production cost. Objects of the invention
This invention is to provide a diamond pen type marking device to solve the above problems.
In details, one of the important objects of the present invention is to change the setting of pen impression of a marking pen by means of electric control circuits which is different from those of said laser device, without an aid of mechanical adjustment.
Still another important object is to automatically change said pen impression and said pen drop speed according to the objectives to be marked and to the marking character profiles.
Further important object is to contribute to acquiring uniform and high quality marking, enhancing productivity man saving and lessening the production cost by conducting continuous automation work by means of rotary absorption disk.
These and other objects of the present invention will be made apparent by the following description and explanation.